The present invention relates to an image processing apparatus for changing the position and the direction of an image of an object taken by a camera and changing the position and the form of illuminating light, thereby correcting the color and the feel of material of the image and displaying the corrected image.
Conventionally, various attempts have been made to print or display an image of an object on a printed matter or a TV monitor with a color and the feel of material, which are similar to those actually recognized by the human eyes.
As the performance of the computer has increased and the DTP system (desk top publishing, electronic publishing) has spread in recent years, various techniques for performing color matching have been proposed to make the displayed color resemble the actual color of the object recognized by the human eyes (e.g. Jpn. Pat. KOKAI Publications Nos. 5-216452 and 6-51732).
A representative of this color matching technique, a CMS (color management system), includes a color correcting unit provided between an image input apparatus, such as a camera, and an image output apparatus, such as a TV monitor. The color correcting unit has an input profile for photographing and an output profile for observation in image reproduction. The color correcting unit converts the color of an input image to a color independent of the image input apparatus or the image output apparatus (hereinafter referred to as a device independent color). Then, it performs color correction based on illuminating environment of an output image.
In the aforementioned CMS, light sources on both input and output sides are designated to D50. Therefore, if an image is photographed or output under illuminating light other than D50, there will be a problem that the observed color cannot match the actual color.
To solve this problem, the applicant proposed a color reproducing apparatus in Japanese Patent Application No. 9-243634. If the photographing place and the reproducing place are distant from each other, a photographed image is transmitted to the reproducing apparatus through a network or the like. When the image is reproduced, the reproducing apparatus performs color matching by means of spectrum, spectrum-converts the illuminating light, and accurately reproduces the color of the photographed object in the observing environment.
In the color reproducing apparatus, an input profile is referred to when an image input through an image input apparatus or the like is converted to a device independent color image, as shown in FIG. 14. The input profile is prepared on the basis of image input apparatus information and environment information. The image input apparatus information includes characteristics of the image input apparatus used to photograph the image and setting status of the characteristics. The environment information includes photographing light data on light for photographing an image of the object by the image input apparatus, observing light data concerning the place where the photographed image of the object is observed, and spectrum statistics data of the photographed object.
When an image is reproduced in the image output apparatus, the accurate spectral reflectance of the object itself in the photographing time is calculated from the characteristics of the image input apparatus, the setting status of the characteristics and the photographing light data. The influence of the photographing light is eliminated by the calculated spectral reflectance. Further, a color under the illumination light in the place where the object is to be observed is calculated on the basis of the observing light data. With the spectrum statistics data of the photographed object, a color-reproduced image can be estimated accurately, even if the input image has little spectrum information.
As described above, the color reproducing apparatus proposed by the applicant converts an image with reference to the image input apparatus information, and the color reproducing environment information which includes spectrum data of photographing and observing light and spectrum statistics data of the photographed object. Therefore, even if the photographing place and the reproducing place are distant from each other, or offset light or external light is varied, the color of the object can be reproduced accurately by the function of the output profile.
In the above color reproducing apparatus, however, reproduction of the feel of material or glossiness of an object has not been particularly taken into account.
Therefore, even when the above color reproducing apparatus is used, if different light fixtures are used in the photographing place and the reproducing place, the condition of specular reflecting on the object is varied and appearance is also changed. Accordingly, it is difficult to completely transfer the feel of material and glossiness of the photographed object only by the color reproduction utilizing color conversion.